Designing a Purchase Order and Payment Workflow in a React + Spring Boot Procurement ERP

I am currently working on a personal project called VendorBridge , a procurement ERP system designed to manage an end-to-end supply chain. This project started at a hackathon, and I am using it to expand my knowledge. My current tech stack consists of: Frontend: React + Tailwind CSS (hosted on Vercel) Backend: Java + Spring Boot (hosted on Railway) Database: MySQL (hosted on Railway) I am currently stuck on the workflow transition between quotation approval and Purchase Order (PO) generation.